Control mechanism for power operated gear shifting apparatus



April 1, 1941. K. MAYBAcH ::TAL'` y l 2235545211'.-

. coNTRoL MEcHANIsM Pon POWER OPERATED GEAR SHIPPING APPARATUS Filed oct. so, 1957 a "sheets-sneeii'f" I Fig. 1 f 9.7 [l/133 3.9 @a gg? n M n" g4/J ,f l A l NZH 'Z ma 37 n n nr .fm/enfans April l, 1941. K. MAYBACH Erm.

CGNTROL MECHANISM FOR POWER OPERATED GEAR SHIFTING APPARATUS 2 sheets-'sheet 2 Patented Apr. 1, 1941 coNTRoL MEcHANIsM FOR POWER OPER- A'PED GEAR SHIFTING APPARATUS Karl Maybach, Carl Bttner, Eugen Glcker and Gustav Meyer, Friedrichshafen, Bodensee, Germany, G. m. many assignors to Maybach -Motorenbau b. H., Friedrichshafen, Bodensee, Ger- Application October 30, 1937, Serial No. 172,020 In Germany October 31, 1936 123 Claims.

This invention relates -to pressure operated gear shift mechanism, such as employed for shifting gears in motor vehicletransmissions, and is directed to an improved control device for controlling the supply of pressure medium to, and hence the operation of, the shift mechanism. 4

In its general design the invention involves a valve for cutting on and off the pressure medium to the shift mechanism which is actuatable in response to movement of an operating lever. The actuating lever may be one particularly designed for the purpose, or again may be either the clutch pedal or throttle lever of the motor vehicle. Preferably lthe arrangement of the control device is such that the control valve will be v actuated upon movement of the operating lever in either direction so that pressure medium may be supplied to the gear shifting mechanism on forward movement and also backward movement of the lever.

The main feature of the invention involves the control of the operating pressure medium for the shift mechanism by a control member in the form of a double acting valve structure which in each of its end positions cuts off the supply of pressure medium to the shifting mechanism and which provides a fl'ow of pressure medium when in an intermediate position between the'two end positions. upon movement of the operating lever in one direction the valve is first moved from one end position to an intermediate position to supplyl Apressure medium for the shifting operation, and

it is thereafter moved on to its other end position to cut off the pressure supply when the shift operation has been completed. On movement of the operating lever in the other direction the control valve can operate in the same way but in the reverse direction, moving from its second end position to an intermediate open position and thereafter from its 'open position to its original closed end position.

The invention may be embodied in a relatively simple and compact structure which is more efficient and reliable in operation than prior control devices. In the past'diiiiculty has been eX- perienced in automatic gear shifting devices by reason of failure of the operating mechanism to complete its shifting operation, because of the tendency of the shifting mechanism to effect too slow a shift, and also because of sticking of the pressure controlled valve or other operating parts of control devices. These difficulties are overcome by the present invention. Also, the inven- The device is so designed that tive structure is so arranged that the danger of accidental leakage of the pressure medium and consequent inadvertent actuation of the shift mechanism is reduced to a minimum.

A further feature of the invention involves the provision of suitablev actuating mechanism for the double acting valvel so designed that a single movement of the operating lever will first produce movement of the valve to an intermediate open position from one of its end positions, and after pressure has been supplied to complete the shifting operation the valve will then be automatically caused to move on to its other end position. While the control valve remains open only momentarily, it should not close until sufficient operating pressure has been supplied. It is therefore proposed to provide mechanism which will hold the valvey in its open position for a suiicient period. Such mechanism may advantageously be of the type forming the subjectmatter of copending application Serial No. 172,019, filed Oct. 30, 1937, of Gustav Meyer, one of the present joint inventors, wherein the closing of the pressure supply control valve from open position is made dependent upon the pressure medium supplied to the shift mechanism. Through such arrangement the con-trol valve will not close until suiiicient pressure has been -supplied to insure operation of the shift mechanism.

As a further specific feature ofthe invention, it is proposed to provide a pressure operated actuating mechanism for the Acontrol valve comprising a plurality of successively operating pressure-responsive actuators dependent on the operating lever, which effect the two-stage operation of the control valve as above referred to. The first actuator is moved by an initiating pressure under control of the operating lever to bring the valve from one end position to its intermediate open position, and thereafter such actuator can be held in its new position by the shifting pressure which operates the shift mechanism. The shifting pressure will preferably be transmitted to the actuatorfrom the valve chamber. Arrangement can be made so that the shifting pressure may be effective on the actuator even though such pressure is cut oi from the shift mechanism when the control valve is in one of its end positions. The latter arrangement enablesthe actuator to remain sub-ject to the shifting pressure when the operating lever =is depressed,,whereasA atA the same time the shift mechanism receives no pressure mediuml 'and hence no loss of pressure is possible by reason of leaks through the shifting mechanism.

In Figures 1 and 2 two exemplary embodiments of the invention are illustrated in schematic arrangement and for the most part in section. Both of such arrangements are designed to utilize as the pressure medium a partial vacuum such as that produced in the intake manifold of the vehicle motor. It will be understood, however, that super-atmospheric pressure, such as compressed air, can also be used Within the scope of the invention without any fundamental change.

In the embodiment of Figure l, |88 is the double acting control valve, the same being housed in a chamber I3. In its right end position, face |09 of the valve engages valve seat IIlSa to close oil a smaller chamber I4 from the valve chamber I3. In the left end position of the control valve, valve face II!) will engage valve seat IIIJa to close 01T the smaller chamber |2 from chamber I3. Pressure medium enters the device through line 6 and passes through chamber 94 and passage |86A to the right chamber I4. According to the present design where a partial vacuum is utilized as the pressure medium, the supply to which line 6 is connected may constitute the intake manifold, not shown, of the Vehicle motor. When valve |88 is in open position the pressure medium from line 8 will be transmitted through chambers I4, I8 and I2 to conduit II. The pressure responsive gear shifting mechanism and the pressure distributing valve mechanism for effecting selective operation thereof to produce different gear selections are well known in the art and have not been shown. It will be understood that conduit II` supplies operating pressure thereto under control of valve |88.

Valve |08 is supported by a slide rod 18 and is normally held in its right end position by spring I I5. The valve actuating mechanism includes piston 18 slidable in chamber 11 which acts against the right end of rod 1D, and a second piston 88 in chamber 8| which through slide l sequent movement of piston 18 to its left end position will move valve |08 from its open position to its left end position against seat I I8a.

Pressure for initiating the operation of pistons 8U and 18 is supplied through line I. Line I,

like line 6, may supply a partial vacuum from the intake manifold, but it will be understood that, as in the embodiment of Figure 2, the supply of vacuum through and venting of line will be subject to control by a valve actuatable by an operating lever (not shown). When the level` is moved in one direction vacuum pressure will be supplied through line I, and upon movement of the lever inl the other direction line I will be vented as in the case of more conventional types of pressure medium controls.

Line I has one branch comprising connecting passages B6, 88, S3 and 82 opening into chamber 8| of piston 88. Interposed between lines 88 and 83 is a slide valve 1| constituting a groove in slide rod of the main control valve |88.

Tol

When valve |08 is in its right end position, pressure medium from line 88 is transmitted to line 83. When valve |88 is in either its intermediate open position or left end position, rod 18 has moved to the left to close valve 1I. However, when rod 18 moves sufciently to the left to bring valve |88 to its intermediate open position, valve 1I uncovers line |82 so that the shifting pressure transmitted to valve chamber I3 and line II from line 8 is also transmitted through line |82 to line 83. The same is true when valve |88 moves to its left end position.

The transmission of pressure medium from line 83 to line 82 and chamber 8| is controlled by a further valve 85 in slide rod 84. With valve 85 open as shown vacuum pressure will be supplied to chamber 8| from line 83. When rod 84 moves to the right line 83 will be cut oil' and chamber 8| in line 82 will be vented to the atmosphere through port 95.

There is a second branch of the initiating pressure line comprising connecting conduits and' B9 opening into chamber 11 oi the second piston 18. The supply of pressure medium from line 85 to 69 is controlled by a valve 88 in slide rod 84. When valve 88 which controls the supply to piston is open as shown, valve 86 is closed and opens to supply pressure through line 89 to piston 18 only when rod 84 moves to the right to close valve and cut olf the supply of pressure to piston 88.- However, an additional means is provided for supplying initiating pressure to chamber 11 of piston 18 through lines 66 and 68 of the iirst-mentioned branch of line I. The right end portion of slide rod 'I8 is provided with a bore I2 commtmicating through a radial bore 15 in the reduced end portion 18 ith chamber 11. At the other end o1" bore 'I2 is a second radial bore 'I3 communicating with an annular groove 14. In the position shown bore 12 is cut off from line 68, and the same will be true when rod 1I] moves sufficiently to the left to bring valve |88 into its intermediate open position. However, when rod 18 moves to the extreme left to bring valve |88 to its left end position groove 14 will be brought into registry with line 68 and the initiating pressure from lino I will be transmitted through bores 13, 12 and 15 to chamber 11 to hold piston 18 in its left end position.

As will now be understood slide rod 84 operats alternately to transmit pressure medium to pistons 88 and 18 through valves 85 and 38 formed therein. As previously indicated, the purpose of the two pistons 88 and 18 is to produce movement of the main control valve |88 from closed to open position in one stage, and from open to its second end position in another stage. The purpose of valves 85 and 86 is to effect the desired operation of the pistons to this end, and accordingly arrangement is made to actuate rod 84 to produce the desired sequence of operation of the respective pistons. In order that valve |08 after reaching its open position can be held therein for sufficient time to supply adequate shifting pre.,- sure from line 6 to line II to effect operation of the shift mechanism, actuating mechanism for rod 84 is provided such that after movement of piston 80 to its left end position by the transmission of pressure through line 83, valve 85 and line 82, there will be a time delay, although very small, before rod 84 is moved to the right to close valve 85 and open valve 88 to allow the transmission of pressure through line 89 to piston 18. The actuating mechanism for rod 84 in the present instance comprises a piston I1 slidable in a chamber 20 having at its left end a vent 31. Piston I1 and rod 84 are normally held in their left end position as shown by a spring 49. As in the copending application Serial No 172,019, above referred to, the closing of valve |08 may be made responsive to the condition of the shifting pressure for the shift mechanism. Line 2 communicating with chamber I2 connects with a further chamber 28 which in turn communicates through port 29 with piston chamber 20. When valve |88 is in its intermediate open position, pressure from line 6 is transmitted through chambers I3 and I2 through the parts just described to act on piston I1 at the same time pressure is supplied to the shift mechanism through line II. However, in line 2 is provided a restricted port 21 which, together with the enlargement provided by chamber 28, will pdelay the transmission of suiicient pressure to chamber 20 to effect movement of piston I1 to the right until adequate pressure has been supplied through line I| to lproduce a shift operation. In the event the pressure supply through line 6 is temporarily inadequate to effect operation of the shift mechanism piston I1 will remain in its left end position until such condition has been overcome. Upon movement of piston I1 to the right to close valve 85 and open valve 86 pressure medium will be supplied to piston 18 which will thereupon move to the left to bring valve 08 against its left seat IIOa, cutting off the supply of pressure to line 2 as well as line II.

'Ihe various parts of the control device in Figure 1 are in the positions they occupy when no shifting operation occurs, the operating lever to which the control device is responsive being in an inoperative position. As before stated the operating lever may be of a type which will produce a pressure impulse in line I, either when the lever is moved in both directions or only in a single direction. In any event when the lever is moved to an operative position to initiate a gear shifting operation of the shift mechanism, the pressure medium, here partial vacuum, is transmitted to chamber 8| through lines 6B, 68, 83 and 82 since both valves 1I and 85 are open. Piston 80 is moved through its complete stroke to its left end position and operates through rod 10 to move the main'control valve |08 to its intermediate open position. The shifting pressure supplied through lines 6 and |86 to chamber I4 then passes through chamber I3 into chamber I2 and is supplied through line II to the shifting mechanism. Pressure is simultaneously transmitted from chamber I2 through line 2, chamber 28 and port 29 to chamber 20. In moving valve |08 to its intermediate position line 68 is cut 01T so that the initiating pressure transmitted from line I is no longer supplied to piston 80, but at the same time valve 1| establishes communication between lines |02 and 83 so that shifting pressure from line 6 in chamber I3 is transmitted through lines 83 and 82 to hold piston 80 in its left end position. Valve |08 remains open until sufcient vacuum has been established in chamber 28 to move piston I1 to the right against the action of its spring 49. Thereupon valve 85 closes and valve 86 opens. Initiating pressure from line I is then transmitted to lines 65 and 69 to chamber 11, and accordingly piston 18 is moved to its left end position to shift valve |08 against its left end seat Illia. Shifting pressure which stillA exists in chamber I3 is thus cut off from chamber I2, line II and from chamber 20.

Through leakage around piston I1 through port 31 the vacuum existing in chamber 20 dissipates quite rapidly and thereupon piston I1 and 'rod 84 move back to the left under action of spring 49. Through such movement initiating pressure transmitted to piston 18 through lines 65 and 69 is out olf. However, when piston 18' reaches its left end position initiating pressure is transmitted thereto through line 68 and bores 13, 12 and 15. Such initiating pressure serves to hold piston 18 and control valve |08 in their left end positions. It will be understood that piston 18 closes valve |08 only after the shifting operation has been completed by the shift mechanism since, as before explained, rod 84 does not move to supply initiating pressure to piston 18 until sufficient time has elapsed to allow the transmission of adequate operating pressure through line II piston I1 which actuates rod 84 being dependent on the same shifting pressure itself as operates the gear shift mechanism.

Assuming now the operating lever is moved to vent line I, as when the vehicle is ready to be driven in the gear selection which has now been set, the vacuum which has been acting on piston 1B is vented through bores 15, 12, 14 and lines 68, 66 and I. Piston 18 then moves part way to the right to allow valve |08 through the action of its spring ||5 to be moved from its left end position toits intermediate open position. Piston is still held in its left end position by the shifting pressure transmitted from chamber I3 through line |02, since after valve |08 reached its left end position leakage around piston I1 allowed rod 84 to move to the left to reestablish communication between lines |02, 83 and 82. Hence, valve |08 is stopped in its intermediate open position as soon as piston 18 reaches pin 19. With valve |88 again open, shifting pressure is again transmitted through line II, and if for any reason the shifting operation had not been completed when valve I 08 was previously open during movement from right to left the shifting operation can now be completed. While valve |08 is in its intermediate position, pressure is again transmitted through line 2 to chamber 20. When sufficient pressure has been developed piston I1 again moves to the right, closing valve 85 so as to out off transmission of shifting pressure from chamber I3 to piston 88 and at the same ltime uncovering port so that through the latter lines 82 and `chamber 8| are vented. Thereupon piston 88 moves to its right end position to allow valve |08 to be forced against its right end seat by its spring II4. Chamber I3 is thereby out oif from chamber 4 and` line 6 and the transmission of such pressure to lines IIV and 2 is discontinued. Piston I1 will thereupon move back to its left end position to open valve 85 and close valve 8E preparatory to anew shifting operation when the operating lever is again moved to establish a vacuum in line I and the several branches thereof. It will be noted that vents 91 and 98 communicate with the right hand portions of chambers 11 and 8| so that pistons 18 and 80 can be moved rapidly to the right under the action of spring ||5.

In the event the vehicle is equipped with an automatic clutch mechanism as well as automatic gear shift mechanism, the clutch control may, as shown in Figure l, be incorporated in the same unit with the gear shift mechanism control as hereabove described. In chamber 94, in the upper portion of the unit through which shifting pressure from line 6 is transmitted to the gear shift mechanism control valve |68, is a valve 9| normally held in engagement with a seat at the right end of chamber 94 by spring 92. To the right of the valve is a smaller chamber 93 from which extends a line |83 adapted to supply operating pressure from line 6 to pressure operated mechanism for the vehicle clutch. A slide rod 96 actuatable by' piston 81 and chamber 69 against the action of spring 88 serves to open valve 9| when moved to thev left. Chamber 63 at its right end is provided with a vent 99 and at its left end is connected by line 61 with branch line 66 of the main initiating pressure line I controlled by the operating lever. With such arrangement, as soon as the lever is operated to establish a partial vacuum in line I, piston 61 is moved to the left to transmit pressure from line 6 to line I 63. This will occur at the same time that the initiating pressure is transmitted to piston 86 to effect opening of control valve |68. Similarly, after the gear sluiting operation has been completed and the operating lever is moved to vent line I, the vacuum is released from chamber 89 and piston 81 moves to the right to close valve 3|. Accordingly, the transmission from line 6 to line |83 is cut off.

The operation of the control device as above described has been made on the assumption that the operating lever has been moved from its rest position and held depressed until the control valve |68 has moved from its right end position to its open position and then to its left end position, and that thereafter the operating lever has been moved in the other direction to its original position to cause valve |63 to move from its left to its open position and then to its original right end position. Under such operation of the lever a shift operation may be initiated in both directions of its movement, and during traverse of valve |66 from right to left, and, again, from left to right. If, however, after the operating lever has been depressed initially to supply pressure from line I to piston 86 and cause valve |68 to open, the operating lever is quickly returned to its rest position before sufficient pressure has been built up in chamber 26 to cause valve 86 to open and before the shift operation has been completed the further action of valve |68 will be different than before. left end position under the initiating pressure from line I and valve |63 has moved to open position, the venting of line I by the release of the lever will not aflect piston 80 since as soon as the valve opens the piston is held in its left 1 end position by shifting pressure transmitted through line |62. Therefore, despite the venting of line I, pressure will gradually build up in chamber 2|) to cause rod 84 to move to the right. Since line I is vented no operating pressure will then be transmitted through line 69 and piston 18 will remain inoperative. Valve I 08 will therefore not be moved on from its open position to its left end position. On the other hand, movement of rod 84 to the right under the action of piston I1 will connect line 82 with port 95 through valve 35. Piston 86 will thereupon move from its left to its right end position and allow valve |03 to move from its open position back to its right end seat.

In the embodiment of Figure 2 the actuating means for the double acting valve and the means for holding the same in its intermediate open position yare somewhat different than in Figure 1 although causing the control valve to operate As soon as piston 86 moves to its in the same manner. Also, certain additional parts are shown in Figure 2, not found in Figure l, including an exemplary pressure distributing mechanism through which the gear shift mechan-ism is selectively operated to produce diierent gear shift selections, and including one form of operating lever through the action of which movement of the control valve is initiated.

In Figure 2 the shifting pressure control Valve I 68, together with its associated chambers I2, I3 and I4, valve faces |69 and IIU, valve seats |0911 and IIIla, and spring |I5, is as before. The shifting pressure supplied from the intake manifold of the engine through line 6 enters chamber I 31 in the upper portion 5 of the unit and is transmitted from such chamber through angular passage |45 to chamber I4 at the right of Valve I 68. In this case line 6 also supplies initiating pressure for actuating valve |68'. Located in chamber |31 is a valve |35 which in its right position closes a small chamber |38 through the action of spring |36. Valve |35 has a stem |34 supported in bore |32 of a slide rod |3I. The operating lever is shown at 3 and is here indicated as constituting the gas pedal of the vehicle operating through arm 9 to actuate the gas throttle I6. Lever 3 is normally held in its rest position against stop 1 by a spring 8. A second arm 4 of lever 3 acts against head |15 of slide rod I1I. Spring I 16 acts against head |15 and tends to press rod |1I` to they right. However, spring |16 is not suiiicient to overcome the tension of spring 8 so that in the rest position of lever 3 rod I1I is held in, its left position as shown in the drawings and acts through slide rod I3| to hold valve |35 open. Under such conditions pressure from line 6 passes through chamber |31 to chamber |38-and thence through line |44 to the actuating mechanism of the control valve |68 hereafter to be described,

When operating lever 3 is depressed slide rods I 1I and I3'I are moved to the right, causing valve |35 to close under they action of its spring |36.

After valve |35 is seated spring |33 causes rod I3I to continue to move to the right until after lever 3 has been depressed slightly. An angular bore |43 `at the left end of rod |3I is uncovered by movement of rod |3I to the right relative to the now stationary stem |34 of valve |35. In the same. movement a radial bore |39 connecting withfa groove I 40 is brought in registry with a vent I4I. The operating pressure, here partial vacuum, previously existing in line |44 and chamber |38 is thereby dissipated through bores |43, |32, |39 and vent |41.

The pressure responsive means for actuating valve |68 comprises a slide rod I6, the right hand portion of which extends into an actuating piston |61 disposed in chamber |69. A disc |66 is held in engagement with the end of rod I 6 by a spring |68. A vent |10 communicates with the right end of chamber |69. Line |44 which supplies a partial vacuum under control of valve |35 and lever 3 connects with the left end of the chamber. The transmission of vacuum through line I 44 moves piston |61 to its left end position as shown and through rod I6 urges valve I 68 towards its left seat. When the vacuum in line |44 is released' spring II-6i tends to move valve |68-, rod I 6 and piston |61 towards their right end positions.

As before, means is provided to temporarily maintain valve |08 in its intermediate open position until sufficient. shifting pressure has been l supplied to actuate the gear shift mechanism.

Because in the present embodiment only a single actuating piston is used in connection with valve |08, a locking mechanism is employed which during traverse of the valve in either direction between its respective seats I09a and ||0a automatically stops and locks valve |08 in its intermediate open position and automatically thereafter releases the same to complete its traverse to its second end position. Such mechanism comprises a latch 6| supported by a spring 62 in groove 63 of a piston 64, Piston 64 is supported by suitable guide means in chamber 2 8 and is pressed upwardly by a spring 32 housed in its hollow underside 34. A vent 36 communicates with the space at the upper end of the piston.

In rod I6 is a groove I5 on each side of which are shallower grooves I8 and I9. When valve |08 is in its end positions latch 6| engages one or the other of grooves I8 and I9. When valve |08 moves from one end position towards the other latch 6| through the action of springs 62 and 32 drops into groove I5, preventing rod I6 from completing its traverse and holding valve |08 in its intermediate open position.

Shifting pressure transmitted `from line 6 to chamber I3, when valve |08 is in its-intermediate open position, is transmitted from chamber I2 through line 2 and restricted orifice 21 to chamber 26. When a sucient vacuum has been established in chamber 28 piston 64 is moved downwardly to release latch 3| from groove I5, thus sof allowing rod I6 and valve |68 to continue their Y movement to one or the other of their end positions.

Operating pressure from line 6 under control of valve |08 is transmitted through chamber I2 to line II which, as shown, communicates with a gear selecting mechanism ycomprising a distributor disc 38 at the left portion 50 of the control unit. The distributor disc is rotatable through a shaft 39 through a wheel or similar' actuating member 40. Two pairs of conduits 45, 46 and 41, 48 Will lead to the respective gear shifting motors. In disc 38 are a series of ports 43 and 44 which selectively vent one of each of the pairs of lines to the atmosphere, while the other lines of the respective pairs through suitable recesses III in the underside of the disc transmit vacuum received through line II. By rotation of the disc 38 the conditions in the lines of each pair can be reversed so that different gear selections can be effected under operation of the gear shift motors.

Assuming that the operating lever 3 is ldepressed, rods |12 and |3| will have moved to the right and valve will be closed. Line |44 will be vented through port |43, bores |32 and |39, and port I4I. Piston |61 will be inits right end position, latch 6| will engage groovev I8and valve |88 will engage its right end seat |090, so that vacuum pressure from line 6 will be closed on from chamber I3. Operating pressure will then not be supplied to line II `and the'distributor mechanism. If now operating lever 3 be brought back to its rest position against stop 1, rods |1| and |3I will move to the left to open valve |35. During such movement port |43 will be closed by the stem |34 of valve |35 and bore- |38 will be thrown out of registry with vent |4|. The position of these and the other parts will then be as shown in the drawings. With the opening of valve v|35 vacuum from line 6 will be transmitted through chamber |38 and line |44, moving piston |61 to its left end position. During such movement the piston rod I6 has been urged to the left to bring valve |08 to its intermediate open position. When rod I6 has moved part way to the left latch 6| drops into groove I5 and temporarily locks rod I6 against further movement, thus holding valve |08 in its open position. Piston |61, however, continues to move to its left end position through the lost motion connection provided between the piston and rod I6 by spring |68.

The opening of valve |68 not only transmits operating pressure to line II for the shifting mechanism but also through line 2 establishes a vacuum in chamber 28. The restricted orifice 21 delays the establishing of suflicient vacuum in chamber 28 to depress piston 64 until after the shifting operation has been completed. When sufficient vacuum has been established piston 64 moves downwardly, releasing latch 6| from groove I5, and allowing rod I6 to move to the left under expansion of spring |68 in piston |61. Thereupon, valve |08 is brought into engagement with its left end seat ||0a. Vacuum is then cut off from chamber I2 and both lines 2 and II. The vacuum existing inchamber 28 is gradually dissipated by leakage of air into the chamber from port 36 around piston 64. The piston again moves upwardly under the action of its spring 32 so that the latch 6I bears against groove I8 so as to be ready to again drop into groove I5 when rod I6 moves to the right.

As long as lever 3 remains in its rest position, valve |35 is open and pressure from line 6 acts on piston |61 so as to maintain valve |68 in engagement with its left end seat. If the lever be depressed in giving gas to the motor, valve |35 is immediately closed, line |44 is again vented to the atmospherethrcugh port |4I, and valve |88, rod I6 and piston |61 move towards the right under action of ,spring I|5 until latch 6| drops into groove I5. Through the action of the latch rod I6 will be stopped with valve I 08 in its-intermediate open position. Operating pressure from line 6 is again transmitted through chamber I2 to line II. At the same time vacuum is transmitted through line 2 to chamber 28. As soon as suflicient vacuum has been established in the latter chamber, piston 64 will move downwardly to release the latch from groove I5, whereupon rod I6 and piston |61 will move to their `right end positions, bringing valve |08 against its right end seat |0911. The operating cycle is now complete and pressure from line 6 is again cut off from line II to the gear shifting mechanism. As before, pressure is similarly cut 01T from line 2, so that piston 64 moves upwardly withV latch 6| now bearing against groove I 8 in rod I6.

In Figure 2 a controlhas again been incorporated in the control unit for the vehicle clutch, the same being somewhat diierent in form from the corresponding mechanism in Figure l. In the upper right hand portion 5 of the unit is located a chamber |8| communicating with the operating pressure -supply line 6. In such chamber is located a valve |19 interposed between the adjoining ends of slide rods |16 and |3I. Such v alve is urged to the right by a spring |80, and in its right end position closes off a smaller chamber |82 from chamber IBI. chamber |82 will supply operating pressure to the clutch actuating mechanism. In the left hand portion of slide rod I1I is a central bore |12 from which extends a radial bore |13. Disposed in the housing is a vent |18 communieating at its inner end with a groove |11. When,

Line |83 from rod |1| moves 'to the right upon depression of lever 3 and closes valve |19 the left end of rod |1| will be released from engagement with valve |19. The vacuum previously existing in line |83 and chamber |82 will then be dissipated through vent |18, groove |11 and bores |13 and |12. The venting of line |83 will cause the clutch servo mechanism to cause the clutch to engage. When the lever 3 is released the venting means just described is rendered inoperative and vacuum from line 6 is again transmitted upon the opening of valve |19 to line |83 to cause the clutch to disengage. At the same time valve |19 is opened by release of lever 3, valve |35 opens to supply operating pressure to piston |51 and initiate opening of control valve |08 to ystart the shifting cycle of the gear shift mechanism.

It will be understood from the several embodiments of the invention herein illustrated and described that the control valve |98 has two end positions in which operating pressure for the gear shift mechanism is out off, and that during movement from either of said positions to the other position operating pressure is momentarily transmitted to the shift mechanism. Valve |08 is held in its intermediate open position for sufficient time to allow for the transmission of adequate pressure to operate the shift mechanism and then closes. Preferably, and as illustrated, the closing of the valve is made dependent upon the shifting pressure itself so that the valve will not close too quickly. As will be evident from a comparison of Figures 1 and 2, the actuating mechanism for the valve and also the means for holding the same in its intermediate open position are capable of a considerable range of modication and equivalency. Again, it will be evident that while both embodiments herein described are designed to utilize partial vacuum as the operating medium, the invention is equal- 1y applicable for use with a high-pressure supply without any fundamental unobvious change. As previously indicated also, the arrangement of the double acting valve and its actuating mechanism is such that a gear shifting operation may be initiated through an operating lever when the lever is moved in either one or both of two directions.

We claim:

l. A control device for pressure-operated gear shifting mechanism in motor vehicles including adouble acting valve for controlling the supply of shifting pressure to the shifting 'mechanism operative in each of its end positions to shut off the shifting pressure and `operative in an intermediate open position to supply shifting pressure, an operating lever having two operating positions, lever operated actuated means for moving the double acting valve providingan interrupted movement of the valve responsive to any movement of said lever from one operating position to the other operating position from one closed end position to intermediate open position and then from intermediate open position to the other closed end position.

2. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, manual control means, motor means for the double acting valve responsive to the manual Acontrol means to move the valve from a closed end position to intermediate open position and then becoming automatically operative independently of the manual control means to move the valve from intermediate open position to a closed end position.

3. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for 4controlling the supply of shifting pressure to the shifting mechanism operative `in each of its end positions to shut oi the shifting pressure and operative in an intermediateopen `position to supply shifting pressure, an operating lever having two operating positions, reversely acting actuating means for the double acting valve responsive to positioning of the lever Ain one operating position to move the valve inone direction and responsive to positioning of the lever `in the other position to move the valve Vin a reverse direction, said actuating means being operative to move the valve from either of its closed end positions to intermediate open posi-tion and then from intermediate open position to one or the other of its closed end positions.

4. A control 1 device for pressure-operated-gear shifting mechanism in motor vehicles including adouble acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its en'd positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, an operating lever, actuatingmeans `for the double acting valve responsive to a single movement of the operating lever in one direction to move the valve in interrupted stages from one `closed end position to intermediate open position and then from interrupted open-position to its other closed endpostion.

5. A control device for pressure-operated gear shifting Vmechanism in motor vehicles including a double acting valve for controlling the supply of shiftingpressure to the shifting mechanism operative in each of its end positions to shut oil the shifting pressure and operative in an intermediate open position to supply shifting pressure, an operating lever, actuating means for the doubles-acting valveresponsive to movement of the operating lever in opposite directions, said actuating means being responsive to a single movement of the lever in-one direction to move the valve in interrupted stages from one closed end position to intermediate open position and from intermediate open position to the second closed end position, said actuating `means being responsive to a single movement of the lever in the op'- posite direction to reversely move the valve in interrupted stages from its second closed end position to intermediate open position and from intermediate open position to its rst closed end position.

6. A vcontrol device for pressure-operated gear shifting mechanism in motor Vehicles including a double acting valve for controlling the supply of shifting pressure'to the shifting mechanism operative -in each lof its lend positions to shut off the shifting pressure and operative in an intermediate open position -to supply shifting pressure, lever-operated actuating means'for moving the double acting valve `from either closed end position to intermediate open position randthenv from intermediate open position to a closed end position, and means operative in theocourse of movement 'to delaythe 'valve in 'its intermediate open position.

7. A control device for pressure-operatedgear shifting mechanism in motor vehicles including' mediate open position to supply shifting pressure' lever-operated actuating means for moving the Idouble acting valve from each of its closed end positions to intermediate open position and from intermediate open position to its other closed end position, and means for causing the valve to stop in its intermediate open position before moving on toits other closed end position.

8. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, an operating lever, lever-operated actuating means for moving the double acting valve between its closed end positions, and pressure responsive means momentarily operative independently of the operating lever to hold the valve in its intermediate open position after initiation and before completion of the movement of the double acting valve by said lever-operated actuating means.

9. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, lever-operated actuating means for moving the double acting valve between its closed end positions, and means responsive to the shifting pressure controlled by said valve operative momentarily to hold the valve in intermediate open position.

10. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supplyA of shifting pressure to the shifting mechanism operative in each of its end positions to shut oi the shifting pressure and operative in an intermediate open position to supply shifting pressure, an operating lever, actuating means responsive to said lever for moving the double acting valve from one closed end position to the other, and automatic means operating independently of the lever for delaying the valve in its intermediate open position in its course of movement from one end position to the other.

11. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut oir the shifting pressure and operative in an intermediate open position to supply shifting pressure, means for moving the double acting valve from one closed end position to intermediate open position, means o-perating in dependency on the shifting pressure for holding the valve in said open position, and means for moving the valve from. open position to one or the other of its closed end positions.

12. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut oil the shifting pressure and operative in an intermediate open position to supply shifting pressure, pressure operated actuating means reversably operative to move the double acting valve from each closed end position to the other closed end position, a lever controlling the pressure for operating said actuating means, the actuating means being operative in response to and after a single movement of the lever in one direction to move the valve in interrupted stages from one closed end position to intermediate open position and then from intermediate open position to its second closed end position and being operative upon movement of the lever in the reverse direction to move the valve from the second closed end position back to the rst `closed end position.

13. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, actuating means for the double acting valve `cornjprising a rst actuating member for moving the valve from one end position to intermediate open position, a second actuating member for moving the valve from said intermediate open position to its other closed end position and means rendered operative upon the valve reaching open position to operate the second actuating means 14. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply -of shifting pressure Vto the shifting mechanism operative in each of its end positions to shut oli the shifting pressure and operative in an intermediate open position to supply shifting pressure, actuating means for the double acting valve comprising va pair of pressure responsive pistons, one piston having a short stroke and being operative to move the valve from one closed end position to a xed intermediate `open position, the other piston having a longer stroke and being operative to move the valve from said intermediate open position to its other closed end position and means rendered operative upon the valve reaching open position to voperate the piston having the longer stroke .to move the valve to its other closed end position.

15. A control device for pressure-operated gear shifting mechanism in mot-or vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, actuating means for the double acting valve comp-rising a pressure-responsive member for moving the valve from oneclosed end position to an `intermediate open position, a second pressureresponsive member actuatable by an initiating pressure to move the valve from intermedi-ate open position to it-s other closed end position and thereafter being subject to the initiating pressure and caused thereby to hold the valve in its latter closed end position and means rendered operative upon the valve reaching open position to supply initiating pressure to the second pressure responsive member.

16. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double Iacting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressureand operative in an intermediate open position to supply shifting pressure, actuating means for the double acting valve comprising a rst pressure-responsive member and a second pressure-responsive member, said members operating successively, one member to move the valve from one closed end position to intermediate open position and the other member to move the valve from intermediate open position to its other closed end position, and means operating in dependency on the shifting pressure for the shift mechanism to supply operating pressure successively to the respective actuating members.

17. A control device for pressure-operated gear shifting mechanism in motor Vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut off the shifting pressure and `operative in an intermediate open positionto supply shifting pressure, actuating means for the double acting valve coinprising a iirst pressure-responsive member for moving the valve from one closed end position to intermediate open position, a second pressureresponsive member for moving the valve from intermediate open position to its second closed end position, means for supplying initiating pressure first to one `and then to the other of said actuating members, and control means for the second member responsive :to operation of the iirst pressure responsive member providing adelay between the operation of the first and second members.

18. In a control device for pressure-operated gear shifting mechanism in motor vehicles, a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions yto shut off the shifting pressure and operative in an intermediate open position to supply shifting pressure, actuating means for the double acting valve including pressure-responsive member for moving the valve between one closed end position and intermediate open position, a lever-controlled ini tiating pressure supply for moving said member, supply means communicating with the ldouble acting valve for supplying shifting pressure to act on said member, and control means for said supply means becoming operative after the valve has been moved to open position by said member through the initiating pressure to deliver shifting pressure to act on said member momentarily to hold the valve in open position.

19. A control device for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of sluiting pressure to the shifting mechanism operative in each of its end positions to shut 01T the shifting pressure and operative in yan intermediate open positionnto supply shifting pressure, actuating means for the double acting valve comprising a firs-t pressure responsive member for moving the valve between one closed end position and intermediate open position, a second pressure responsive member for moving the valve between intermediate open position and its sec- 0nd closed end position, a lever-controlled initiating pressure supply for moving both of said members, control means for supplying said initiating. pressure to the respective members successively and' also operating to cause said initiating pressure to `act against the second member to hold the valve in its second closed end position, supply means communicating with the double acting valve for supplying shifting pressure to the iirst member, control means for said supply means becoming operative when the iirst member through the initiating pressure has moved the valve to open position to cause shifting pressure to act on the iirst member momentarily to hold the valve in open posi-tion.

20. A control device for pressure-operated gear j shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of its end positions to shut oi the shifting pressure and operative in an intermediate. open position to supply shifting pressure, actuating means for moving the double acting. valve between its closed end positions, and pressure responsive locking means for momentarily holding the valve in its intermediate open i position.

21. A controldevice for pressure-operated gear shifting mechanism in motor vehicles including a double acting valve for controlling the supply of shifting pressure to the shifting mechanism operative in each of. its end positions to shut oi the shifting pressure and operative in an intermediateopen position to supply shifting pressure, actuating means for moving the double acting. valve between its closed end positions, lock- -ing means for holding the valve in intermediate open position, and pressure means responsive to the shifting pressure controlled by the double acting valve for releasing said locking means.

22. A control device for pressure operated gear shifting mechanism in motor vehicles including a double acting valve means for controlling the shifting pressure supply closed in its opposite end positions, lever means, and automatic motor 'means-for actuating the valve initiated into opo. eration by said lever means and being initially termediate stop position to its second closed end position.

23. A control device for pressure operated gear shifting mechanism in motor vehicles including a double acting valve` means for controlling the shifting pressure supply closed in its opposite end positions, motor actuating means for the valve operative to move the valve in successive automatically interrupted stages from one closed end position to an intermediate open position and then from said intermediate open position to its other closed end position and control means for the motor actuating means responsive to movement of the valve to open position to effect movement of the valve from open position to its other closed end position.

KARL MAYBACH. CARL BTTNER. EUGEN GLCKER.

GUSTAV MEYER. 

